Hugh Cabot was a urologic surgeon and a Boston Brahmin whose driving sense of social responsibility embroiled him in controversial medical reform efforts through nearly half a century of professional life. After three years of medical service with the B.E.F. in World War I, he left his successful Boston practice and his Harvard and M.G.H. teaching positions to build a strong, full-time department of surgery at the University of Michigan Medical School. As Dean beginning in 1921, he implemented many of the reforms he advocated as President of the Association of American Medical Colleges (1925 and 1926) and as a member of the Commission on Medical Education. The various entrenched interests he thus offended secured his dismissal at mid-year in 1930. He then joined the Mayo Clinic and Mayo Foundation, where he enjoyed eight years of group practice and post-graduate teaching in the manner of the clinical-pathological conferences which he co-edited with his brother, Richard, in the 1920's (Case Histories of the M.G.H., Bost. Med. & Surg. Jo.). In The Doctor's Bill (1935) and The Patient's Dilemma (1940) and in numerous public addresses and magazine articles, Cabot contrasted the technological excellence of modern American medicine with its inflexible and tradition-bound stands on matters social and economic. When organized medicine refused to permit discussion of innovative forms of practice and repeatedly blocked experiments with pre-paid, low-cost group practice, Cabot's outrage that his own profession should be so poorly led compelled him to testify for the government in a successful anti-trust suit against the AMA. He also took part in the National Health Conference (1938) and in the Committee of physicians for the Improvement of Medical Care.